3.116 \(\int \frac {1}{\sqrt {-8+6 x+9 x^2}} \, dx\)

Optimal. Leaf size=25 \[ \frac {1}{3} \tanh ^{-1}\left (\frac {3 x+1}{\sqrt {9 x^2+6 x-8}}\right ) \]

[Out]

1/3*arctanh((1+3*x)/(9*x^2+6*x-8)^(1/2))

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Rubi [A]  time = 0.01, antiderivative size = 25, normalized size of antiderivative = 1.00, number of steps used = 2, number of rules used = 2, integrand size = 14, \(\frac {\text {number of rules}}{\text {integrand size}}\) = 0.143, Rules used = {621, 206} \[ \frac {1}{3} \tanh ^{-1}\left (\frac {3 x+1}{\sqrt {9 x^2+6 x-8}}\right ) \]

Antiderivative was successfully verified.

[In]

Int[1/Sqrt[-8 + 6*x + 9*x^2],x]

[Out]

ArcTanh[(1 + 3*x)/Sqrt[-8 + 6*x + 9*x^2]]/3

Rule 206

Int[((a_) + (b_.)*(x_)^2)^(-1), x_Symbol] :> Simp[(1*ArcTanh[(Rt[-b, 2]*x)/Rt[a, 2]])/(Rt[a, 2]*Rt[-b, 2]), x]
/; FreeQ[{a, b}, x] && NegQ[a/b] && (GtQ[a, 0] || LtQ[b, 0])

Rule 621

Int[1/Sqrt[(a_) + (b_.)*(x_) + (c_.)*(x_)^2], x_Symbol] :> Dist[2, Subst[Int[1/(4*c - x^2), x], x, (b + 2*c*x)
/Sqrt[a + b*x + c*x^2]], x] /; FreeQ[{a, b, c}, x] && NeQ[b^2 - 4*a*c, 0]

Rubi steps

\begin {align*} \int \frac {1}{\sqrt {-8+6 x+9 x^2}} \, dx &=2 \operatorname {Subst}\left (\int \frac {1}{36-x^2} \, dx,x,\frac {6+18 x}{\sqrt {-8+6 x+9 x^2}}\right )\\ &=\frac {1}{3} \tanh ^{-1}\left (\frac {1+3 x}{\sqrt {-8+6 x+9 x^2}}\right )\\ \end {align*}

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Mathematica [A]  time = 0.00, size = 24, normalized size = 0.96 \[ \frac {1}{3} \log \left (\sqrt {9 x^2+6 x-8}+3 x+1\right ) \]

Antiderivative was successfully verified.

[In]

Integrate[1/Sqrt[-8 + 6*x + 9*x^2],x]

[Out]

Log[1 + 3*x + Sqrt[-8 + 6*x + 9*x^2]]/3

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fricas [A]  time = 0.94, size = 20, normalized size = 0.80 \[ -\frac {1}{3} \, \log \left (-3 \, x + \sqrt {9 \, x^{2} + 6 \, x - 8} - 1\right ) \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/(9*x^2+6*x-8)^(1/2),x, algorithm="fricas")

[Out]

-1/3*log(-3*x + sqrt(9*x^2 + 6*x - 8) - 1)

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giac [A]  time = 0.57, size = 21, normalized size = 0.84 \[ -\frac {1}{3} \, \log \left ({\left | -3 \, x + \sqrt {9 \, x^{2} + 6 \, x - 8} - 1 \right |}\right ) \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/(9*x^2+6*x-8)^(1/2),x, algorithm="giac")

[Out]

-1/3*log(abs(-3*x + sqrt(9*x^2 + 6*x - 8) - 1))

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maple [A]  time = 0.04, size = 30, normalized size = 1.20 \[ \frac {\sqrt {9}\, \ln \left (\frac {\left (9 x +3\right ) \sqrt {9}}{9}+\sqrt {9 x^{2}+6 x -8}\right )}{9} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(1/(9*x^2+6*x-8)^(1/2),x)

[Out]

1/9*9^(1/2)*ln(1/9*(9*x+3)*9^(1/2)+(9*x^2+6*x-8)^(1/2))

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maxima [A]  time = 2.99, size = 22, normalized size = 0.88 \[ \frac {1}{3} \, \log \left (18 \, x + 6 \, \sqrt {9 \, x^{2} + 6 \, x - 8} + 6\right ) \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/(9*x^2+6*x-8)^(1/2),x, algorithm="maxima")

[Out]

1/3*log(18*x + 6*sqrt(9*x^2 + 6*x - 8) + 6)

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mupad [B]  time = 0.22, size = 20, normalized size = 0.80 \[ \frac {\ln \left (3\,x+\sqrt {9\,x^2+6\,x-8}+1\right )}{3} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(1/(6*x + 9*x^2 - 8)^(1/2),x)

[Out]

log(3*x + (6*x + 9*x^2 - 8)^(1/2) + 1)/3

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sympy [F]  time = 0.00, size = 0, normalized size = 0.00 \[ \int \frac {1}{\sqrt {9 x^{2} + 6 x - 8}}\, dx \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/(9*x**2+6*x-8)**(1/2),x)

[Out]

Integral(1/sqrt(9*x**2 + 6*x - 8), x)

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